JPS636470Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigerant compressor, and particularly to a structure for returning blow-by gas during a compression stroke to a cylinder head suction chamber.

During the compression stroke of the piston in the cylinder, a portion of the compressed gas leaks into the rotor case, ie, into the crank chamber, as blow-by gas.
Therefore, generally, a path (ie, a so-called balance hole) is provided that communicates the crank chamber with the suction chamber of the cylinder head, so that the blow-by gas is sucked back into the normal path of the refrigerant. By the way, lubricating oil is moved within the crank chamber by the rotation of the rotor and the like. In this way, the lubricating oil that has reached the vicinity of the entrance of the balance hole is caused to flow out into the suction chamber together with the gas flow that returns to the suction chamber of the cylinder head through the balance hole. The lubricating oil that has flowed out from the crank chamber into the suction chamber is sucked into the cylinder together with the refrigerant gas, and some of it returns into the crank chamber along with the blow-by gas as described above, but most of it ends up flowing into the refrigerant circuit.

Furthermore, since the automobile cooling compressor is driven by the automobile engine, its rotation speed varies from a low speed of several hundred rpm during idling to a high speed rotation of over 5,000 rpm. In this case, when the compressor rotates at high speed, blow-by gas increases, so the gas flow rate in the balance hole also increases, resulting in a large amount of lubricating oil flowing out of the crank chamber. That is, as the compressor rotates at a higher speed, the amount of oil flowing into the refrigerant circuit generally increases and the amount of residual oil in the crank chamber decreases. This phenomenon of increased oil spillage increases the oil circulation rate in the refrigerant circuit, resulting in a decrease in the heat exchange rate of the condenser and evaporator, and pressure loss in the refrigerant circuit, resulting in a significant decrease in cooling capacity. Needless to say.

In addition, the phenomenon of a decrease in the amount of lubricating oil (residual oil) in the crankshaft chamber due to an increase in the amount of oil leaking into the refrigerant circuit occurs when the engine is operated at extremely high loads, such as when idling or when driving at extremely low speeds due to traffic jams. As a result, good lubrication cannot be obtained through sufficient oil supply to the bearings and sliding parts inside the compressor.
The life of the compressor will be shortened, and the extremely low amount of residual oil during high-speed operation will not only deteriorate the life of the bearings and sliding parts, but also cause an oil film on the sealing surface due to lack of oil supply to the shaft sealing device. This leads to breakage and gas leakage due to abnormal wear of the sealing surface, making it unusable. Conventionally, this has been dealt with by increasing the initial amount of oil filled in, which further increases the oil circulation rate and reduces the cooling capacity of the system.If the total length of the refrigerant circuit becomes longer, the amount of oil filled in is further increased. There is also the problem of having to increase the amount of

Conventionally, attempts have been made to prevent lubricating oil from flowing into the balance hole by making the balance hole inlet protrude inward or enveloping the crank chamber. Due to the movement of the lubricant, it is not possible to achieve a good effect.

Therefore, the purpose of this invention is to prevent the lubricant from leaking into the circuit as much as possible by placing the entrance of the balance hole in the part of the crank chamber where lubricant is least present, thereby solving the above-mentioned drawbacks and problems. The purpose of the present invention is to provide a refrigerant compressor with

According to the present invention, a crank chamber is provided on the opposite side of the cylinder block from the cylinder head, and a ring-shaped thrust bearing is connected to the front housing forming the end surface opposite to the cylinder block in the crank chamber. A thrust-supported rotating cam rotor and a mechanism for converting the rotation of the cam rotor into reciprocating motion of a piston are provided, and a balance hole is provided for returning refrigerant gas leaking into the crank chamber to the refrigerant circuit. In the refrigerant compressor, the cam rotor includes a space formed by an axial recess formed in the inner side of the thrust bearing on the surface facing the front housing, and a window communicating the space with the crank chamber. The balance hole passes through the inside of the front housing, has one end opening at a position facing the space in the front housing, and has the other end opening into the suction chamber of the cylinder head. A refrigerant compressor is obtained.

According to such a compressor, the blow-by gas leaking into the crank chamber enters the space of the cam rotor through the window formed in the cam rotor, and is sucked into the balance hole by the negative pressure in the suction chamber. It will be returned to the suction chamber through the hall. By the way, a certain amount of lubricating oil that lubricates the bearing parts flows into the cam rotor space, but as a result, the amount of lubricating oil that exists in the rotor space is small and is blown outward by the centrifugal force caused by the rotation of the rotor. Since the lubricating oil is blown away, the amount of lubricating oil taken out through the balance hole having an inlet opposite to this space can be kept to an extremely low level. Note that since the centrifugal force of the cam rotor acts, lubricating oil does not enter the space through the windows formed in the cam rotor. Further, since it is not necessary to add a special device for separating lubricating oil, the structure does not become complicated. Furthermore, since the lubricating oil is prevented from flowing into the suction chamber of the cylinder head, there is no need for a structure for returning the lubricating oil from the cylinder head to the crank chamber.

Examples will be described below with reference to the drawings.

Referring to FIG. 1, a cylinder block 2 is fitted into one end of a housing 1, and the other end is closed with a front housing 3, so that a crank chamber 4 is formed between the cylinder block 2 and the front housing 3. has been done.

A drive shaft 5 extending through the front housing 3 is supported via a bearing 6. The front housing 3 includes a sleeve 7 projecting outward around the drive shaft 5, and has a shaft seal assembly 8 incorporated therein.

A cam rotor 9 having an inclined surface is attached to the inner end of the drive shaft 5, and is thrust supported on the inner surface of the front housing 3 via a thrust bearing 10. A swing plate 12 is brought into contact with the inclined surface of the cam rotor 9 via a thrust bearing 11 . The rocking plate 12 is supported by a ball 14 seated at the center of a bevel gear 13 that is elastically supported in the axial direction by the cylinder block 2, and is provided with teeth 15 that mesh with the bevel gear 13.

The piston 17 fitted in the cylinder 16 formed in the cylinder block 2 is connected to the piston rod 18.
It is connected to the swing plate 12 via.

A cylinder head 20 is abutted on the outer end of the cylinder block 2 via a valve plate 19 provided with a reed valve, and is fixedly attached with bolts 21. The cylinder head 20 includes a suction chamber 22 and a discharge chamber 23, which are operatively connected via suction and discharge ports of the cylinder 16 and valve plate 19, respectively, by the action of a reed valve.
It goes without saying that the cylinder head 20 also has a suction port and a discharge port for communicating with the suction chamber 22 and the discharge chamber 23, respectively, and for connection to an external cooling circuit.

With the above configuration, when the drive shaft 5 is rotated by an external drive source, for example an automobile engine, the cam rotor 9 rotates together. As a result, the swing plate 12
swings around the ball 14, reciprocates the piston 17, and compresses the refrigerant. At this time, the rocking plate 1
2 has its teeth meshing with the bevel gear 13 to prevent rotation.

Lubricating oil is sealed inside the crank chamber 4.
During operation, lubricating oil is splashed into the crank chamber by the cam rotor 9 and the rocking plate 12.
Each part in the crank chamber and the cylinder wall are lubricated.

In this embodiment, the shaft seal assembly 8 is lubricated by a deflector 24 provided so as to protrude from the inner wall of the housing at the upper part of the crank chamber, as shown in FIG.
The oil flowing down along the inner wall of the housing is
This is achieved by guiding the oil to an oil hole 25 provided in the front housing and flowing it through the oil hole to the shaft seal portion 26. A portion of the lubricating oil in the shaft seal portion 26 flows from there through the bearing 6 into a space 27 consisting of an axial recess provided on the surface of the cam rotor 9 facing the front housing 3, and is caused by the rotation of the cam rotor 9. It is swung out into the crank chamber 4 while lubricating the thrust bearing 10 by centrifugal force. The shaft 5 is formed with an oil hole 28 that opens into the shaft seal portion 26, extends through the shaft, and opens into the crank chamber.
6, returns to the crank chamber 4 through this oil hole while further lubricating the thrust bearing 11.

Incidentally, in order to return the blow-by gas that blows into the crank chamber 4 through the gap between the piston 17 and the inner wall of the cylinder 16 to the refrigerant circuit during operation of the compressor, a gas pump is provided to connect the crank chamber 4 and the suction chamber 22. The balance hole is indicated by the symbol 29 in FIG. This balance hole 29
The front housing 3 has a U-shaped elongated hole 30 formed in the front housing 3, and a connecting tube 31 that communicates between the hole 30 and the suction chamber 22. In this way, the entrance 32 of the balance hole 29 is formed on the inner surface of the crank chamber 4 of the front housing 3 at a position facing the space 27 of the cam rotor 9. Furthermore, a space 2 is provided on the outer periphery of the cam rotor 9.
7 into the crank chamber 4 (not shown)
is formed, and blow-by gas enters the space 27 through this window. Note that since the centrifugal force of the cam rotor 9 acts, lubricating oil will not enter through the window. Therefore, since oil for lubricating the bearings 6 and 10 only passes through this space 27, the amount of lubricating oil present therein is generally small.

Now, the blow-by gas that has entered the space 27 is
The negative pressure in the suction chamber 22 draws air into the balance hole 29 and returns to the suction chamber 22 through the balance hole 29 . On the other hand, the lubricating oil that has reached the space 27 is radially blown away by the separation action of the rotation of the cam rotor 9, that is, by the centrifugal force, and returns to the crank chamber 4 while lubricating the thrust bearing 10. In this way, due to the action of centrifugal force, the proportion of the lubricating oil that reaches the space 27 and is taken out through the balance hole 29 is extremely small.

Furthermore, by sucking the blow-by gas into the balance hole 29, the space 27 is expanded into the crank chamber 4.
is at a lower pressure than Therefore, the lubricating oil is forced to flow from the oil hole 25 through the shaft seal portion 26 and the bearing 6 to the space portion 27, and the lubrication effect is also excellent.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention, and FIG. 2 is a sectional view showing a part of the same embodiment taken at different angular positions. 1...Housing, 2...Cylinder block,
3...Front housing, 4...Crank chamber,
5... Drive shaft, 9... Cam rotor, 12... Rocking plate, 16... Cylinder, 17... Piston, 19
... Valve plate, 20 ... Cylinder head,
22... Suction chamber, 23... Discharge chamber, 25... Oil hole, 26... Shaft seal portion, 27... Space portion, 29... Balance hole.

Claims (1)

[Scope of utility model registration request] A crank chamber is provided on the opposite side of the cylinder block from the cylinder head, and within the crank chamber is a rotating engine that is thrust-supported via a ring-shaped thrust bearing by a front housing that forms the end surface opposite to the cylinder block. A refrigerant compressor that is provided with a cam rotor and a mechanism that converts the rotation of the cam rotor into reciprocating motion of a piston, and further provided with a balance hole for returning refrigerant gas leaked into the crank chamber to the refrigerant circuit, The cam rotor has a space formed by an axial recess formed in the inner part of the thrust bearing on the surface facing the front housing, and a window communicating the space with the crank chamber, and The hole passes through the inside of the front housing and has one end opened at a position facing the space in the front housing,
A refrigerant compressor characterized in that the other end thereof is open to a suction chamber of the cylinder head.